深厚砂层地基止水帷幕失效原因及处理措施

结合工程实际，对深厚砂层地基止水帷幕失效原因及处理措施进行了研究。从施工、材料、环境等方面分析了影响止水帷幕质量的原因及影响因素，并提出了优化水泥浆泵送压力、控制施工垂直度、止水帷幕掺合料比例控制、土体环境颗粒度分析等应对措施，从而有效地预防和处理止水帷幕质量问题，为类似工程提供了借鉴。     

落底式地下连续水泥土墙止水帷幕施工监理控制探讨

大中型城市地下空间的开发利用使得深基坑地下止水帷幕施工逐渐增多,同时对止水帷幕施工技术提出了更高的要求.结合湖北省人民医院心血管大楼建设项目,分析了选用液压抓斗工艺施工地下连续水泥土墙的可行性,介绍了液压抓斗施工地下连续水泥土墙的工艺流程,并提出了落底式地下连续水泥土墙止水帷幕施工的监理控制要点,以期为类似工程加强各个...     

CSM工法在武汉地区深基坑工程中的应用

随着土木工程的快速发展尤其是地下空间的开发利用,深基坑施工过程中的地下止水帷幕应用越来越多,对止水帷幕施工技术也提出了更高的要求。在华中科技大学同济医院内科综合楼基坑工程中,采用了双轮铣深层搅拌技术(CSM工法)落底式止水帷幕,这是CSM工艺首次在武汉地区使用。本文旨在结合实际工程,总结其设计方法和实施效果的情况,并对止水效果进行分析,最后提出针对CSM工法的建议。     

某复杂地质条件下基坑止水帷幕失效原区分析及补救方案

本文以某基坑工程止水帷幕失效事故为例,介绍了该基坑复杂的地质和环境条件、止水帷幕设计和施工方案、止水帷幕失效的发现经过以及止水帷幕失效对工程和环境的影响,并对止水帷幕失效的原因进行了分析,本文最后介绍了止水帷幕失效事故的处理措施。     

双液注浆快速补漏技术在某深基坑工程中的应用

深基坑支护工程设计施工中，止水帷幕的有效性是基坑及周边建筑物安全的关键因素。实际基坑工程中，局部点或局部区段止水帷幕失效造成漏水、漏砂的情况时有发生，给基坑安全造成了隐患。以某实际基坑工程为背景，介绍了该基坑施工过程中局部止水帷幕失效后采取袖阀管双液注浆进行治理的施工参数、工艺流程、关键技术和治理效果。实践表明，基坑工程采用袖阀管双液注浆方案进行紧急补漏修复止水帷幕能有效减少对周边环境的影响，并保证基坑的安全性和稳定性，为类似基坑工程提供了参考依据。     

TRD工法在地铁车站端头止水帷幕中的应用

在地基含水层深厚或施工环境受到限制等特殊条件下,常采用TRD工法墙替代三轴搅拌桩作为深基坑止水帷幕.深基坑止水帷幕施工质量的好坏,直接关系到基坑降水对周边环境的影响.结合某地铁车站深厚含水层中TRD工法墙的工程实践,介绍了TRD工法止水帷幕施工流程,提出了TRD工法止水帷幕施工控制要点;根据地下水位观测资料,简要分析了TRD工法止水帷幕的止水效果.     

某深基坑止水帷幕研究与应用

在工程建设中为实现对深基坑的围护,并保证施工的安全性,本研究开展了某深基坑止水帷幕。在明确工程基本概况的基础上,设计深基坑止水帷幕。通过高压旋喷桩施工、三轴水泥搅拌桩施工、钻孔灌注止水帷幕桩施工等操作后,完成对深基坑止水帷幕的施工。在施工后,对深基坑工程进行监测,避免深基坑中土层位移、围护结构沉降产生,提高深基坑施工安全。     

长螺旋旋喷搅拌水泥土帷幕桩技术在工程中的应用

基坑工程中,对地下水处理的方法应用比较广泛的有许多种,止水帷幕就是其中之一.本文介绍了止水帷幕常用的施工方法及其优缺点,重点介绍了长螺旋旋喷搅拌水泥土帷幕技术在基坑工程中的应用情况,该技术很好地解决了目前在类似北京地区较硬土层中施工帷幕造价高、施工质量可控性差、止水效果不理想等问题,为类似需要做止水帷幕的基坑工程提供了...     

谈格构式深层搅拌桩基坑支护止水帷幕

介绍了格构式深层搅拌桩基坑止水帷幕的特点及适用范围,并对基坑的支护及止水原理进行了阐述,总结了制桩及帷幕施工要点,实践表明:采用格构式深层搅拌桩基坑止水帷幕具有较好的经济效益和社会效益。     

TRD工法和CSM工法在上海地区超深基坑工程止水帷幕的应用

介绍了TRD和CSM 2种新的止水帷幕施工工法的施工原理、施工设备和施工方法.结合硬X射线自由电子项目1号工作井和5号工作井工程实例,对两者的施工和止水效果进行比较和总结,指导了硬X射线自由电子项目2号工作井、3号工作井和4号工作井的止水帷幕的施工.结果表明TRD工法更适用于上海地区超薄基坑工程止水帷幕.     

居住区地表种植面积保障技术

本研究的目的是在现有的城市土地资源不变的情况下，在不改变现有的居住区规划设计规范条件下，通过相对简单的技术手段，探索增加居住区地表种植面积的有效措施，并用这些方法使我国已经建成的优秀居住区能新增加的绿化地表种植面积约占小区总面积的２．７％，对这我国城市居住住区环境建设的可持续发展有着积极意义。     

土的基本特性及本构关系

面对土的外延持续拓展、内涵不断深化、本构模拟精度要求日趋提升的挑战,土的基本特性与本构关系研究要回归初心,面向工程需求,聚焦于达到工程分析精度而需要刻画的土的宏细观一体化特性,称作土的工程本征性。工程本征性主要有三相性、各向异性、摩擦性和剪胀性等几个方面,其内涵和发展趋势基于研究现状进行探讨。研究与刻画土的工程本征性时,应基于一体化的思路,注重细观特征和宏观特性刻画精度的均衡性,即：宏观层面的研究指导在细观层面有目标的观测,而不需要无止境的追求各类细观层面的细节;细观层面的研究为宏观层面的刻画提供充分依据,从而克服脱离细观机理的唯象假设。以土的工程本征性为核心探讨土的基本特性与本构关系研究的宏细观一体化建模方法,结合强度理论和多过程耦合模型等课题探讨研究现状与发展趋势。简要回顾本构理论研究的重要进展,指出土的本构理论研究已经具备深厚积累,以期为宏细观一体化的工程本征性研究奠定坚实的基础。     

考虑超孔隙水压力的桩土界面直剪试验研究

采用大型恒刚度直剪仪,系统研究超孔隙水压力对黏性土中桩土界面剪切性能的影响。根据制定的测试超孔隙水压力方案,对4个粗糙度等级(混凝土表面锯齿状峰谷距为0、2、4、6mm)的不同含水率黏性土中桩土界面在不同剪切速率下进行剪切试验。针对界面粗糙度、黏性土含水率、剪切速率3个变化参数对界面抗剪强度的影响进行分析。结果表明：界面粗糙度越大,界面超孔隙水压力越小,有效法向应力越大,黏性土颗粒与混凝土表面吸附性越大,桩土界面抗剪强度越大;黏性土含水率越大,界面超孔隙水压力越大,有效法向应力越小,黏性土颗粒与混凝土表面吸附性不能完全发挥,桩土界面抗剪强度反而减小;在剪切速率0.4~1.0mm/min范围内,剪切速率越大,界面超孔隙水压力增幅较小,有效法向应力变化不大,桩土界面抗剪强度虽有减小,但不同剪切速率下超孔隙水压力对桩土界面抗剪强度的影响不明显。     

厨房、卫生间楼板渗漏的主要原因及防治

针对厨房、卫生间楼板渗漏的主要原因，从适当降低厨房、卫生间楼板，合理布置地漏、做好灌水试验等方面，介绍了具体的防治措施，以解决渗漏难题。     

Debating the future of comfort: environmental sustainability, energy consumption and the indoor environment

Vast quantities of energy are consumed in heating and cooling to provide what are now regarded as acceptable standards of thermal comfort. In the UK as in a number of other countries, there is a real danger that responses in anticipation of global warming and climate change - including growing reliance on air-conditioning - will increase energy demand and CO₂ emissions even further. This is an appropriate moment to reflect on the history and future of comfort, both as an idea and as a material reality. Based on interviews and discussions with UK policy makers and building practitioners involved in specifying and constructing what will become the indoor environments of the future, four possible scenarios are identified each with different implications for energy and resource consumption. By actively promoting debate about the indoor environment and associated ways of life, it may yet be possible to avoid becoming locked into social and technical trajectories that are ultimately unsustainable. The aim of this paper is to inspire and initiate just such a discussion through demonstrating that comfort is a highly negotiable socio-cultural construct.     

TBM施工岩爆微震监测的准确率及适用性研究

深埋隧道岩爆是困扰TBM施工安全和进度的重要因素,为此微震监测系统逐渐引入TBM施工对岩爆进行监测预警。然而,TBM施工微震监测的工程案例还很少,其监测预报的准确性和适用性存在争议。以新疆ABH工程和陕西引汉济渭工程为依托,对岩爆微震监测预报的等级和位置进行现场跟踪验证和分析,将岩爆按风险高低划分为Ⅰ、Ⅱ、Ⅲ共3个等级,给出了不同风险等级岩爆预测的准确率和适用性。结果表明：岩爆微震监测预报的准确率随着岩爆风险等级的增强而提高,对Ⅰ、Ⅱ级岩爆基本可以实现准确定位;引汉济渭工程Ⅰ级岩爆预测的准确率达到78.4 %,14.0%的Ⅰ级岩爆被预报为Ⅱ级,Ⅱ级岩爆预测准确率为55.2%,26.1%的Ⅱ级岩爆被预报为Ⅰ级;ABH工程Ⅱ级岩爆预测准确率为53.3%,46.7%的Ⅱ级岩爆被预报为Ⅲ级;Ⅲ级岩爆预测等级和定位的准确性都比较低。综合考虑岩爆预测的准确性以及施工安全、施工速度和防控措施的因素,建议：TBM工程仅存在Ⅲ级岩爆风险时,无需引入微震监测;存在Ⅰ级、Ⅱ级岩爆风险时,宜采用微震监测,以确保施工安全。     

The dynamics of alkalinity generation by an anoxic sediment exposed to acid water

The time dependence of the rate of generation of alkalinity by productive sediments treated with acid waters was investigated for various conditions using continuously stirred flowing reactors. Complete mass balances allowed the generated alkalinity to be related to specific processes, none of which were affected by light. The high rate of oxidation of organic material was sufficient to consume all the oxygen, nitrate and sulphate supplied to the vessels during the first few days of incubation, but by 15 days sulphate reduction had ceased and oxygen and nitrate reduction were incomplete. In incubations supplied with anoxic waters there was an initial small release of calcium, but by 10–15 days the generation of alkalinity could be accounted for by nitrate reduction (23%), sulphate reduction (47%), Fe(II) production (23%) and NH₄⁺ production (7%). Iron(II) was exhausted when only 1% of the total amount of iron in the sediment had been released. In incubations supplied with oxygenated waters sulphate was only reduced during the first 10 days while oxygen was completely consumed. By 15 days there was incomplete consumption of oxygen and the generation of alkalinity was accounted for by nitrate reduction (36%), calcium release (53%) and NH₄⁺ production (11%). Comparisons of reaction rates indicate that calcium is released by being replaced by ammonium ions which are generated by decomposition of organic matter. Although, in the longer term, more base is generated by sediment incubated anoxically, sediments incubated with oxygenated water generate base more rapidly for the first few days until the most readily oxidized organic matter is consumed.     

Design of humanitarian tents for use in cold climates

Extreme climatic risks pose significant challenges to displaced populations that often lack adequate shelter. Contemporary policy documents concerning emergency shelter reveal that the scope of shelter-associated risk is much wider than simply exposure to the elements and includes a significant social dimension. However, disparity exists between implicitly accepted risks described in aid agency literature and field practice. Experience in recent disaster assistance programmes in Kosovo and Afghanistan illustrates how ill equipped the aid community is to deal with cold weather affecting transitional settlements. A review of the environmental risks associated with living in tented accommodation in cold climates reveals the difficulty of providing thermal comfort and fire safety in both heated and unheated tents. In addition, social surveys and field trials with displaced populations in Afghanistan illustrate that shelter is used, perceived and valued differently according to the ethnic and cultural background of occupants, and that these are also factors that impact on the risks they bear. Several design recommendations and guides for the use of cold climate relief tents are made, whilst acknowledging that the provision of alternative, longer-term shelter provision during the phase of emergency response is nearly always preferable.     

关于建筑结构抗震设计若干问题的讨论

对当前建筑结构抗震设计中若干原则性问题进行讨论,提出：建筑结构抗震设计不适宜采用概率可靠度方法而更适合采用多安全系数设计方法;应以设防烈度地震即中震的地震动参数进行结构承载力设计,依R-μ-T规律改进设计中的地震作用-延性等级组合;当结构的计算基底剪力不满足规定的最小基底剪力时,可以加大地震作用力,而不应该调整结构的刚度来加大地震反应;比较了巨型框架与普通框架结构的侧向刚度,说明巨型框架的侧向刚度远较普通框架差,不具备承担一定比例地震作用剪力的必要刚度,而应令核心筒承担全部的地震剪力;我国现行规范对结构的层间位移角限值过于严格,分析其主要原因并建议大幅度放宽。